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Lithium-ion battery with Huawei’s patented graphene material technology can improve durability and performance

Lithium ion has been the main battery material for a long time, and the smartphone industry is seeking to shift from lithium ion batteries to more advanced solutions. However, due to some challenges, smartphone manufacturers avoid using graphene in their smartphone batteries.

But now it seems that Huawei has finally stepped into this matter, because Huawei has recently certified a new design patent, which was recently issued by the State Intellectual Property Office of China.

Before we introduce the patent in detail, you may need to know some information about graphene:

A traditional lithium-ion battery in a standard smartphone takes about 90 minutes on average, and the time will be shortened with the speed of the charger. On the other hand, a battery with a Graphine battery is much faster, and it takes about 20 minutes to fully charge a 3000mAh battery with a 60W charging brick.

In terms of lifespan, most batteries can manage about 300 and 500 charge cycles, but a graphene battery of the same capacity can last about 1500 cycles, and the battery generates much less heat, which helps make smartphones more efficient. Cooler and safer. (Via DigitalTrends)

Patent details:

The patent says: “Conductive adhesives for lithium ion batteries and their preparation methods, lithium ion battery electrodes and preparation methods, and lithium ion batteries.”

According to the description of the patent, this technology uses polyvinyl alcohol, polyethylene glycol, polystyrene, starch, sodium alginate, etc. as a binder, and graphene as a conductive material. The amount of graphene is 0.1%-10% of the total mass, and the thickness of the graphene particles is 5nm-50nm, and the D50 particle size is 50nm-5000nm.

The patent shows two use cases for adhesives:

  • First class accounts for 20%-50%
  • The second adhesive uses materials such as polyacrylic acid and polyimide.
  • The first and second adhesives are bonded by chemical bonds.

In the image below, you can see:

  • Silicon particles
  • Graphene
  • binder

Patent Figure

 

Silicon particles are described as hollow inside, even if they expand, they will not lose performance.

In order to increase the energy density of current lithium batteries, graphite anode materials are often replaced with alloy materials such as silicon.

However, silicon will expand and fall during the cycle, which will definitely cause a rapid decline in battery life. To solve this problem, the patent uses a new type of conductive adhesive to bond silicon particles and combine the adhesive and conductive agent together.

When the silicon particles expand by inserting lithium, the polymer chains of the binder elongate. When the silicon particles delithiate and shrink, the polymer chains of the binder entangle and shrink again, so the graphene and silicon are always in contact .

After 50 cycles of the battery manufactured using this patent, the battery capacity retention rate exceeds 90%, and the discharge efficiency is as high as 97% and 98%.

It should also be pointed out that the conductive binder acts as both a conductive agent and a binder, which can increase the content of lithium-intercalated active materials in the positive and negative electrodes, thereby increasing the energy density of the battery.

Therefore, the Chinese technology giant has not yet fully switched to graphene, but plans to use 10% of it. Since Huawei only uses a limited amount of graphene, the main purpose of the patent is to extend the life cycle and partial performance of existing lithium-ion batteries, which may have a positive impact on overall battery performance.

Source – ithome



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